WASHINGTON — Representatives of the nation’s weather forecasting community gathered Tuesday to confess that the figure known as “percent chance of rain” is derived chiefly by looking out a window, then at one another, and then settling on a number that nobody will be able to prove wrong.

“We want to be transparent with the American people,” said Dr. Lorraine Pettibone-Achterberg, Senior Associate Director of Ambient Hunch Calibration at the National Center for Atmospheric Shrugging. “The process involves a lot of squinting. Someone says ‘Hm.’ Someone else says ‘Yeah.’ Then we write down forty.”

The admission followed a decades-long pattern in which the percentage has hovered between 30 and 60 for virtually every day of the calendar. Pressed on why the figure never reaches 0 or 100, Pettibone-Achterberg explained that those numbers “carry a kind of emotional commitment we are not in a position to make.”

According to the presentation, which was delivered on a projector that briefly showed a screensaver of a sunny meadow, the forecasting method has been refined over generations. A 10 percent chance means a forecaster saw a cloud but was in a good mood. A 70 percent chance means someone’s knee hurt. Anything above 80 is reserved for days when a forecaster has already been caught without a jacket.

Asked whether satellites, radar, or supercomputers factor into the calculation, panelists paused for several seconds. “They’re in the room,” said Gunnar Voss-Tillerman, a Regional Supervisor of Cloud Vibes at the Midwest Bureau of Looking Up. “We like to have them nearby. It’s reassuring.”

The press conference was itself held under a large awning, which reporters noted was not mentioned in the event’s advance materials. When asked about it, a spokesperson said the awning was “a coincidence, and also non-negotiable.”

Audience members expressed frustration that a 40 percent chance of rain has been interpreted for years as meaning rain will fall over 40 percent of the area, or during 40 percent of the day, or with 40 percent of the intensity of real rain. Forecasters confirmed it means none of these.

“It’s the number you say when you want to be right whether or not it rains,” said Voss-Tillerman. “If it rains, we said forty. If it doesn’t, we said forty. Nobody has ever filed a complaint about forty.”

“Forty just feels safe. It’s the beige of probabilities.”

Pettibone-Achterberg added that the field is exploring alternatives, including a proposed system of weather-related emojis, a single raised eyebrow, and simply saying “We’ll see.” A pilot program using the phrase “Eh, bring a jacket” reportedly tested well with focus groups.

At press time, the center had released its forecast for the following day, which it described as “a 40 percent chance of that, too.”